Very interesting the exhaustive investigating and the determination of an individual to go to extremes to satisfy a "hunch". I'm led to believe the conclusion is correct.

Considering that potentially crippling levels of ODAP are found in wild-potato seeds, and given the symptoms McCandless described and attributed to the wild-potato seeds he ate, there is ample reason to believe that McCandless contracted lathyrism from eating those seeds. As Ronald Hamilton observed, McCandless exactly matched the profile of those most susceptible to ODAP poisoning:

I met a young man on a survival forum that was really into eating wild foods especially mushrooms. I lost contact with him and later found out he died at an early age of cancer. Makes me wonder if it was diet related. He went by the name of "storm" on the forums.